This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is a continuous research effort by our cardiovascular research team and Dr. Maryann Martone and her fellows. Studies aim to elucidate the heart failure-related abnormalities in cardiac t-tubles structure. Studies include EM and LM level analysis of myocardium obtained from mutant mouse model of dilated cardiomyopathy. The unique technology developed by Dr. Maryann et al. to document 3D structure of t-tubes are expected to unveil unknown disease-related abnormalities in this critical component of cardiac excitation-contraction coupling.